(Digital Presentation) Develop a Novel Approach to Graphite Recycling in Industrial Level

Abstract

Due to their high specific energy density (Wh/kg), high volumetric energy density (Wh/L) and long cycle life, lithium-ion batteries (LIBs) are being widely used in U.S. military and civilian applications. With the rapid growth of demands these years, recycling methods are developed to solve the shortages of supply for rare metal cathode materials, especially Li and Co. However, not being evaluated as high value material, graphite in spent LIBs always gets neglected. Therefore, graphite is burnt or downcycled and consequently generate CO2 gas as an inescapable result. Recent reports show the market demand for energy storage from Li-ion batteries will reach to 400 GWh in 2022, which required nearly 3 million tons of graphite, also it is estimated that 3 billion batteries are thrown away each year by Americans. Considering the raw material making graphite is organic materials from nature with an irreversible process, a vicious circle can’t be broken if graphite doesn’t get recycled. Remarkably, our group has developed a novel closed-loop hydrometallurgical process for recycling end-of-life Li-ion batteries. After developing methods of acid leaching and alkaline sintering, recycled graphite with an ultra-high purity (over 99.9%) is obtained for the first time. Being successfully scaled up to industrial level, it’s proved to be a green and high-efficient method in battery recycling. Further coating and surface treatment means are followed, recovering the capacity and improving the stability of recycled graphite to commercial standard. In summary, our research provides a novel maneuver to fully purify and recover the recycled graphite, which has great potential to be commercialized.